自体肿瘤疫苗治疗肝癌的实验研究

目的探讨自体肿瘤疫苗预防和治疗肝癌的效果及抗癌机制。方法采用多聚甲醛固定的小鼠Hepal-6细胞为抗原、粒细胞-巨噬细胞集落刺激因子（GM-CSF）和白介素-2（IL-2）缓释微球为免疫激活剂、辅以免疫辅助剂TiterMax Gold的肝癌疫苗皮内接种C57BL／6J小鼠，观察肿瘤疫苗预防和治疗肝癌的效果。结果对照组15只小鼠全部发展成肝肿瘤；含有固定Hepal6细胞和IL-2及GM—CSF微球的肿瘤疫苗，80％小鼠获得保护。再加入免疫辅助剂TiterMax Gold的肿瘤疫苗，则87％小鼠获得保护。将Hepal6细胞接种于左躯干皮下。肿瘤长至直径5mm时，皮内接种肿瘤疫苗2次。结果显示，对照组肿瘤继续生长。疫苗组在第2次接种后7～10d，肿瘤生长受到抑制，随后明显缩小。60％小鼠的肿瘤完全消失。细胞毒性实验结果显示，接种疫苗的小鼠脾细胞的杀瘤活性可被抗-CD3^＋、抗-CD8^＋、抗-MHC-Ⅰ单克隆抗体所阻断，但不被抗-CD4^＋、抗-MHC-Ⅱ单克隆抗体所阻断。结论自体肿瘤疫苗具有很强的抗肿瘤的效果。其抗瘤机制是诱导内源性抗原特异性CTL反应，由典型的MHC—Ⅰ限制的CD8^＋T细胞所介导的。

Autologous tumor vaccine for prevention and treatment of HCC

Objective To investigate the role of autologous tumor vaccine for prevention and treatment of HCC and explore its anti-tumor mechanism. Methods The autologous tumor vaccine for HCC was developed by using fixed HCC cells as antigen, biodegradable microparticles encapsulating granulocyte-macrophage-colony stimulating factor (GM-CSF) and interleukin-2 (IL-2) as the immune activating agent and TiterMax Gold as the supplementing agent. Then the vaccine was intradermally inoculated into the C57BL/6J mice to investigate its role for prevention and treatment of HCC. Results All the 15 non-immunized mice developed HCC. The rate of protection in mice immunized with fixed Hepal-6 cells and both of IL-2/GM-CSF microsphere or further mixed with TiterMax Gold reached 80% and 87%, respectively. The established tumors of 5 mm in diameter was markedly reduced by vaccination twice and eventually resulted in complete regression in 60% of the mice. The tumors in control mice continued to grow. Cultured splenocytes from the vaccinated mice showed specific lysis of Hepal-6 target cells. The cytotoxic activity of vaccine was inhibited by the treatment with anti-CD3, anti-CD8 and anti-MHC-class I monoclonal antibodies but not with anti-CD4 and anti-MHC-class II antibodies. Conclusions Fixed HCC vaccination can elicit protective and therapeutic antitumor immunity against HCC. The mechanism of which might be that it can induce internal antigen-specific CTL response modulated by the typical MHC-class I restricted CD8~+ T cells.